Refrigerated motion picture stage



NOV. 15, 1938. N H, ROSBERG 2,136,758

REFRIGERATED MOTION PICTURE STAGE Filed May 20, 1936 Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE 4 Claims.

In the making of motion pictures of ice, snow, or other cold weather scenes, the operators have heretofore had two options: the first, to place the sets in real snow in the open air; the second to provide a substitute for snow which does not melt when exposed to the atmospheric temperature of the ordinary stage'. l

The rst alternative has the advantage that the scene is not limited to the compass of a stage, and some desired eifects cannot be obtained in any other manner, but it has certain very serious drawbacks, inasmuch as it is limited to the winter season'or to inaccessible locations in high mountains at other seasons and as actual photography may be interrupted by extended periods of unsuitable Weather conditions. For these reasons outdoor exposures of snow scenes are, on the average, extremely costly and are avoided so far as possible.

Attempts have been made to reproduce snow scenes on ordinary stages, using various white powdered materials as substitutes for snow, but these attempts have been far from successful. First and foremost, none of these substitutes has the texture, refractive index, color, weight, or coherence of actual snow, and sets to which these substitute powders are applied are highlylacking in verisimilitude. Again, the breath of the actors is not visible, as it is in actual snow scenes under cold climatic conditions; it is impossible for the actors to imitate the peculiarities of gait which follow from the slipperiness o f packed snow and the weight of loose drifts, and finally, the characteristic crunch of snow under foot cannot be obtained in the use of any substitute.

To obviate all of these drawbacks and to permit genuine snow scenes to be lmed within doors and regardless of atmospheric conditions, I have provided the following combination of apparatus, to wit: a building insulated against excessive inflow of atmospheric heat, means for reducing the temperature within the building to a point below the freezing point of water; means for ventilating the building without elevating the temperature of the air within it, and means for producing artificial snow consisting of minute flakes of frozen water and for distributing this snow in various manners on sets which may be constructed within the building,

The building used for this purpose may be of any desired dimensions and construction, provided that it affords room for the stage proper and for the cameras, lighting equipment and other paraphernalia customarily used. For reasonable economy of refrigeration it is desired to utilize the type of construction common in cold storage warehouses: brick walls, concrete floor, and a felt and gravel or other relatively nonconductive type of` roof. No provision for admission of daylight is necessaryv nor is it usually desirable. 5

A liberal area of brine, ammonia or other refrigerated cooling coils should be provided ins the upper part of the building, more or less adjacent to the roof or ceiling; or coil bunker rooms may be installed for the ready removal of heat from the upper portions of the building where the temperature is highest, or coil surface may be placed on portions of the side and end walls. If coil bunker rooms are used, sufficient forced air circulation should be maintained to hold the room at the desired temperature.

In calculating the refrigerationV load the heat delivered by the klieg lights should not be overlooked. This heat, which is highly considerable in quantity, is radiant heat projected with the light rays and therefore cannot be overcome by cooling or insulating the light sources, but must be removed from the stage itself. by providing an ample supply of cold air for the removal of the heat from objects on which the heat rays impinge.

The cooling coils are provided with control valves by which the quantity of applied refrigeration may be regulated. The doors should provide against unnecessary admission of outside air, but for ventilation a fan should deliver a of sheets of ice are to be taken, a portion of the stage may be arranged as a shallow tank provided with immersed freezing coils, or a better acoustic effect may be obtained by laying a sheet of ice directly on the floor, in a layer of fine river sand of an inch or more thickness. formed by applying successive layers of ice cold water to the top of the sand, each layer being allowed to freeze by reason of the low temperature prevailingy in the room, until a layer of the desired thickness has been built up. A very 50 smooth and entirely usable ice sheet may thus be built up which is entirely free from the rumbling noise which often occurs when skating on ice made by refrigerating coils immersed in a tank.

A corresponding quantity of 35 n The ice is combination. For this purpose I utilize an apparatus already known and in use for other purposes, to wit, the ice crusher with snow slinger currently used for such purposes as icing shipments of vegetables.

This apparatus consists, in general terms, of a shell within which a drumis rapidly revolved, the face of the drum being provided with a considerable number of small steel pegs adapted to crush to a pulp the ice cakes which are fed against the face of the drum. The pulverized ice is then transferred through a conveyor to an ice slinger 28, which consists of a shell with a revolving impeller, turning at high velocity. A current of cold air is passed into this machine along with the pulverized ice, and due to the high air velocity through the shell the pulverized ice is separatedinto innumerable plate-like fragments which resemble snowflakes in all respects except for the lack of the characteristic feathery crystalline structure.

For the purpose of my invention these ice akes behave in all respects like natural snow. The air current in which they are suspended may be conducted through wide tubes lto any desired part of the building and the stream discharged in any desired direction. If directed upwardly from a point outside the stage proper, the falling flakes produce a. true simulation of either a gentle snowfall or a wind driven snowstorm, depending on the angle to which the discharge is raised. The falling snow may be accumulated to any desired depth on roofs, fences, etc., and on the iloor of the stage, and having the adherent properties of true snow collects on trees and shrubbery in ,the most realistic manner. By directing the discharge at low angles, drifts may be built up and snow may be caused to adhere to vertical surfaces such as tree trunks as it does during snowstorms. The snow packs under foot and gives the characteristic crunch. The characteristics of the scenes thus formed may be varied by varying the temperature of the cold air-stream and of the enclosure, that is, at relatively low temperatures a hard dry snow may be produced while by slightly raising the temperature the eiects of damp snow and of incipient thawing may be produced.

By the use of this method and combination of apparatus any snow scene adapted to the compass of a stage may be produced Within a few hours and maintained without change for an indenite period thereafter. Changes in the appearance of the set may be made with rapidity by removals and additions of snow at suitable places, and the entire set may be cleared in a short time, either mechanically or by raising the temperature of the enclosure.

In brief, the combination proposed has 'advantage over the use of snow substitutes at normal temperatures in that the snow applied to the set is, for the intended purpose if not literally, real snow exhibiting the exact behavior of that-produced in nature, and in that the temperature of the atmosphere in which the scene is photographed is that at which a snow scene would be photographed in the open air. These conditions lend a verisimilitude to an indoor snow scene which cannot be approached in any other manner.

For example, the snow produced in the above manner so closely resembles genuine snow in its properties that it drifts, packs, whims in the' breeze, and can be made into snowballs. Leafless trees and bushes take on a natural wintry appearance when the snow covers and weights down the branches. With appropriate drops in the background the eiect of vast distances may be obtained.

Icicles are made from raw water in specially designed forms and can be placed on the sets where needed. In some instances it is desirable to make the icicles directly on the set, by providing slow water drips and allowing the water to freeze as it would in nature.

Heretofore it has been impossible to obtain the realistic effect of the visible breath of persons and animals in cold weather without nesort to the highly inconvenient use of such means as a container of dry ice held in the mouth of the actor. In the use of the apparatus and method here described the temperature of the entire atmosphere is lowered to the point of ready visibility without the use of any contrivances whatever, and the effects thus obtained photograph well and add greatly to the realism of the scene.

Fog scenes, with or without the use of snow, may be produced with the same apparatus by the introduction of highly humid air or even of steam onto suitable parts of the stage or throughout the entire building. The fog thus generated is produced in the manner in which it is produced in nature, by the reduction of temperature of relatively humid air below the point of saturation.

As compared with the open air utilization of natural low temperature, ice, snow, and fog, there are the obvious advantages of accessibility and of greatly reduced cost, the expense attending the preparation of a snow scene in this manner being but a fraction of the cost of moving actors and apparatus to a snowed location in temperate latitudes. Other advantages which may not be so apparent but which tend strongly toward economy and convenience lie in the complete control over all the conditions under which a series of scenes isto be shot and the entire freedom from such limitations as are placed by uncontrollable weather conditions when working in the open air.

'Ihe attached drawing illustrates, in a highly diagrammatic manner, an arrangement of apparatus suitable for the practice of my invention: Fig. 1 being a ground plan, Fig. 2 a longitudinal section, and Fig. 3 a cross section of a building equipped for this purpose.

Referring to the drawing, III-I0 are the walls. preferably of brick or concrete, II a ceiling and I 2 a roof, leaving a dead air space I 3 therebetween. A double or seal door I l is provided for ingress to the building.

Adjacent the ceiling but not immediately against it I place an extensive refrigerating coil I5, preferably an expansion coil for liquid anhydrous ammonia, and provide this coil with valves I 6 and II for controlling ammonia supply and expansion pressure. A similar coil I8, of any convenient form and size, may be placed in a bunker I9 which is supplied with a strong current of air by means of a fan 20.

The air passed through the bunker, and strongly cooled by passing over the coils, is preferably discharged in the neighborhood of the ceiling coils and in such a manner as to ilow over them, as through a conduit ZI having one or several openings. The supply of the fan may be drawn from near the floor of the building, through a controllable opening 22, or from the exterior of the building as through the controllable opening 23, or from a point inside the building and near the ceiling as through a conduit 24 controlled by damper 25. By regulating these controls and also the amount of ammonia expanded in each of the coils the temperature of the air within the building may be closely controlled and pure outside air may be drawn into the building at intervals for ventilation. For the latter purpose impure air may be allowed to escape from the building through a controllable opening or openings 26 in one or more of the Walls.

I also find it desirable to provide a plurality of fans 21--21 so directed as to discharge strong currents of air across the ceiling coils l5. These fans materially accelerate the transfer of heat from the air to the coils.

The ice crusher and snow slinger, already described, are indicated at 28. This unit should be fully portable and is shown as mounted on trucks for that purpose.

I claim as my invention:

1. Apparatus for preparing snow scenes for photographic purposes comprising in combination: a building insulated against heat loss and a motion picture stage arranged therein; means for maintaining the atmosphere within said building at a desired temperature not exceeding 32 degrees Fahrenheit; means for producing a supply of pulverized ice particles and for co1- lecting them into a stream, and'means for directing said stream. of ice particles onto delimited portions of said stage and articles placed thereon.

2. The method of creating and maintaining a realistic indoor snow scene for motion picture activities, comprising confining within an enclosed insulated area a stage setting occupying a restricted portion only of said area, leaving an unobstructed portion of said area for activities adjacent said setting, directing a controlled movement of pulverized ice in the area of the stage setting, and eiecting deposit thereof discriminatively upon constituents ot said stage setting to create a definite pictorial eect, and

inatively upon constituents of said stage setting to create a denite pictorial effect, preserving said effect for any period desired for successive photographing operations, by substantially enveloping the pulverized ice deposit in an atmosphere of a temperature not above the freezing point of water, and raising said temperature to create the effect of damp snow and incipient thawing.

4. The method of creating and maintaining a realistic indoor scene for motion picture activities, comprising confining within an enclosed insulated area a stage setting occupying a restricted portion only of said area, leaving an unobstructedr portion of said area for activities adjacent said setting, directing a controlled movement of pulverized ice in the area of the stage setting, and effecting deposit thereof discriminatively upon constituents of said stage setting to create a denite pictorial effect, preserving said eiect for any period of time desired for successive photographing operations, by substantially enveloping the pulverized ice deposit in an atmosphere not above the freezing point of water, and subjecting constituents of the stage setting to the influence of humid air or steam to creat the effect of a fog.

NELS H. ROSBERG. 

